Account not closed - Still being billed

Went into Telkom on November 2015 to advise that my adsl line must be cancelled as it's moving to a new service provider, 30 day notice for this was the requirement and was adhered to. The migration of the line was done 12 January 2016. After the migration I was under the impression that Telkom closed the account as I only have the ADSL line. I paid the January payment which was due thinking that this would be the last payment. Only to be billed again for Febuary 2016. This is unacceptable as there's no service that Telkom is even providing me I do not have a line any longer so why am I being billed. This account needs to be closed immediately as the 30 day notice period by Telkom was not adhered to.